Staphylococcus caseorum sp. nov., a new species isolated from Spanish traditional, blue-veined Cabrales cheese.

Abstract

Three bacterial strains isolated from Cabrales cheese (IPLA 37010, IPLA 37011 and IPLA 37012T) were initially assigned to Staphylococcus equorum based on partial 16S rRNA gene sequencing. Nevertheless, genome comparison with the type strains S. equorum subsp. equorum DSM 20674T and S. equorum subsp. linens DSM 15097T revealed them to possess distinct genomic and genotypic features. They were therefore subjected to a series of extensive phenotypic tests, including carbohydrate fermentation, enzyme activity, novobiocin resistance, growth in aerobiosis and anaerobiosis and at different pH, temperature and salt concentrations. All three strains were found to be facultatively anaerobic, coagulase- and oxidase-negative and catalase-positive. Matrix-assisted laser desorption/ionization time-of-flight analysis was unable to assign the strains to any staphylococcal species with validly published names. Based on these genomic, phenotypic and chemotaxonomic results, IPLA 37010, IPLA 37011 and IPLA 37012T are concluded to represent a novel species, for which the name Staphylococcus caseorum sp. nov. is proposed. The type strain, S. caseorum IPLA 37012T, is deposited in the German Collection of Microorganisms and Cell Cultures (DSM 117647T) and in the Spanish Type Culture Collection (CECT 31035T).